Low Cycle Fatigue and Relaxation Performance of Ferritic–Martensitic Grade P92 Steel

Due to their excellent creep resistance and good oxidation resistance, 9–12% Cr ferritic–martensitic stainless steels are widely used as high temperature construction materials in power plants. However, the mutual combination of different loadings (e.g., creep and fatigue), due to a “flexible” operation of power plants, may seriously reduce the lifetimes of the respective components. In the present study, low cycle fatigue (LCF) and relaxation fatigue (RF) tests performed on grade P92 helped to understand the behavior of ferritic–martensitic steels under a combined loading. The softening and lifetime behavior strongly depend on the temperature and total strain range. Especially at small strain amplitudes, the lifetime is seriously reduced when adding a hold time which indicates the importance of considering technically relevant small strains.

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A New Empirical Life Prediction Model for 9–12%Cr Steels under Low Cycle Fatigue and Creep Fatigue Interaction Loadings

Metals ◽

10.3390/met9020183 ◽

2019 ◽

Vol 9 (2) ◽

pp. 183 ◽

Cited By ~ 7

Author(s):

Xiaowei Wang ◽

Wei Zhang ◽

Tianyu Zhang ◽

Jianming Gong ◽

Magd Abdel Wahab

Keyword(s):

Experimental Data ◽

Life Prediction ◽

Low Cycle Fatigue ◽

Hold Time ◽

Cycle Fatigue ◽

P92 Steel ◽

Creep Fatigue ◽

Effects Of Temperature ◽

Temperature Strain ◽

Life Prediction Model

Low cycle fatigue (LCF) and creep fatigue interaction (CFI) loadings are the main factors resulting in the failure of many critical components in the infrastructure of power plants and aeronautics. Accurate prediction of life spans under specified loading conditions is significant for the design and maintenance of components. In the present study, various LCF and CFI tests are conducted to investigate the effects of temperature, strain amplitude, hold time and hold direction on the fatigue life of P92 steel. To predict fatigue life under different experimental conditions, various conventional life prediction models are evaluated and discussed. Moreover, a new empirical life prediction model is proposed based on the conventional Manson-Coffin-Basquin (MCB) model. The newly proposed model is able to simultaneously consider the effects of temperature, strain amplitude, hold time and hold direction on predicted life. The main advantage is that only the known input experimental parameters are required to perform the prediction. In addition to the validation made through the experimental data of P92 steel conducted in the present paper, the model is also verified through numerous experimental data reported in the literature for various 9–12% Cr steels.

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Damage behaviour in different micro-regions of P92 steel weldment under sequential low cycle fatigue and creep loading

Engineering Fracture Mechanics ◽

10.1016/j.engfracmech.2021.107935 ◽

2021 ◽

pp. 107935

Author(s):

Wei Zhang ◽

Xiaowei Wang ◽

Zitong Kang ◽

Tianyu Zhang ◽

Yong Jiang ◽

...

Keyword(s):

Low Cycle Fatigue ◽

Cycle Fatigue ◽

P92 Steel ◽

Steel Weldment ◽

Creep Loading

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Component Low Cycle Fatigue Behavior Based on Standard Calculation Procedure and Non-Linear FEA

Volume 3B: Design and Analysis ◽

10.1115/pvp2017-66071 ◽

2017 ◽

Author(s):

Jürgen Rudolph ◽

Adrian Willuweit ◽

Steffen Bergholz ◽

Christian Philippek ◽

Jevgenij Kobzarev

Keyword(s):

Power Plants ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Hybrid Approach ◽

Combined Cycle ◽

Cycle Fatigue ◽

Element Analysis ◽

Constitutive Material Model ◽

Standard Design ◽

Creep Fatigue

Components of conventional power plants are subject to potential damage mechanisms such as creep, fatigue and their combination. These mechanisms have to be considered in the mechanical design process. Against this general background — as an example — the paper focusses on the low cycle fatigue behavior of a main steam shut off valve. The first design check based on standard design rules and linear Finite Element Analysis (FEA) identifies fatigue sensitive locations and potentially high fatigue usage. This will often occur in the context of flexible operational modes of combined cycle power plants which are a characteristic of the current demands of energy supply. In such a case a margin analysis constitutes a logical second step. It may comprise the identification of a more realistic description of the real operational loads and load-time histories and a refinement of the (creep-) fatigue assessment methods. This constitutes the basis of an advanced component design and assessment. In this work, nonlinear FEA is applied based on a nonlinear kinematic constitutive material model, in order to simulate the thermo-mechanical behavior of the high-Cr steel component mentioned above. The required material parameters are identified based on data of the accessible reference literature and data from an own test series. The accompanying testing campaign was successfully concluded by a series of uniaxial thermo-mechanical fatigue (TMF) tests simulating the most critical load case of the component. This detailed and hybrid approach proved to be appropriate for ensuring the required lifetime period of the component.

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LOW CYCLE FATIGUE BEHAVIOR AND LIFE PREDICTION OF A CAST COBALT-BASED SUPERALLOY

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512003261 ◽

2012 ◽

Vol 06 ◽

pp. 251-256

Author(s):

HO-YOUNG YANG ◽

JAE-HOON KIM ◽

KEUN-BONG YOO

Keyword(s):

Fatigue Life ◽

Strain Energy ◽

Life Prediction ◽

Prediction Models ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Total Strain ◽

Cycle Fatigue ◽

Total Strain Range ◽

Different Temperatures

Co -base superalloys have been applied in the stationary components of gas turbine owing to their excellent high temperature properties. Low cycle fatigue data on ECY-768 reported in a companion paper were used to evaluate fatigue life prediction models. In this study, low cycle fatigue tests are performed as the variables of total strain range and temperatures. The relations between plastic and total strain energy densities and number of cycles to failure are examined in order to predict the low cycle fatigue life of Cobalt-based super alloy at different temperatures. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.

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Effects of strain ratio and tensile hold time on low-cycle fatigue of lead-free Sn-3.5Ag-0.5Cu solder

Journal of Electronic Materials ◽

10.1007/bf02692449 ◽

2006 ◽

Vol 35 (2) ◽

pp. 292-301 ◽

Cited By ~ 13

Author(s):

Chin-Kuang Lin ◽

Chun-Ming Huang

Keyword(s):

Low Cycle Fatigue ◽

Hold Time ◽

Strain Ratio ◽

Lead Free ◽

Cycle Fatigue ◽

Tensile Hold ◽

Tensile Hold Time

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Low-Cycle Fatigue of the Equipment of Nuclear Power Plants Made of 15Kh2MFA Steel

Materials Science ◽

10.1007/s11003-005-0179-6 ◽

2005 ◽

Vol 41 (3) ◽

pp. 410-417 ◽

Cited By ~ 2

Author(s):

B. T. Timofeev ◽

Zh. L. Bazaras

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Low Cycle Fatigue ◽

Cycle Fatigue ◽

15Kh2mfa Steel

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A Study on the Temperature Calibration for a Small Electrical Resistance Furnace

ASME 2010 Pressure Vessels and Piping Conference: Volume 1 ◽

10.1115/pvp2010-25181 ◽

2010 ◽

Author(s):

Un Bong Baek ◽

Hae Moo Lee ◽

Yun-Hee Lee ◽

Seung Hoon Nahm

Keyword(s):

Electrical Resistance ◽

Power Plants ◽

Low Cycle Fatigue ◽

Small Scale ◽

Temperature Calibration ◽

Cycle Fatigue ◽

Resistance Furnace ◽

Small Space ◽

Start Up ◽

Electrical Resistance Furnace

A severe thermal stress occurs during start up/shutdown transients in thick walled components of high temperature power plants. Thus, a precise consideration of this issue is very important. Many researchers have studied low-cycle fatigue at high temperatures and small box-type electrical resistance furnaces have been developed for small-sized fatigue specimens. However, these small-scale electrical resistance furnaces need precise temperature calibrations because temperature control is difficult in a small space. Thus, a method for the temperature calibration of a box-type electrical resistance furnace is investigated and calibration procedures are proposed in this study.

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